package com.example.my.servlet;

import com.example.my.dao.NewsDao;
import com.example.my.bean.newsBean;

import javax.jws.WebService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

/**
 * 1. 配置网址映射
 * 2. 接受前端提交的数据
 * 3. 查询数据库(增删改查)
 * 4. 页面的跳转或显示(数据给前端)
 */
@WebServlet("/news.html")
public class NewServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");//请求参数类型设置
        String sp = req.getParameter("page");//前端的参数都是String类型
        int page = 1;
        if (sp  != null && !sp.equals("")){//传了情况下
            page = Integer.parseInt(sp);//将前端字符数字强制转化为整形
        }
        NewsDao newsDao = new NewsDao();
        List<newsBean> list = newsDao.getList(page);//分页查询
        req.setAttribute("list", list);//通过req将list数据传递给前端
        // 属于额外知识
        //getRequestDispatcher决定webapp目录系下的那个文件显示
        req.getRequestDispatcher("WEB-INF/news.jsp").forward(req, resp);
    }
}
